Iván Duque, of the right-wing Centro Democrático (CD), and Gustavo Petro, of the left-wing Colombia Humana movement, came in first and second place respectively in the first-round of the presidential election on May 27th; the two will compete in a run-off election on June 17th. The build-up to the second round will be polarised, and potentially hostile, but The Economist Intelligence Unit continues to believe that Mr Duque will become president, maintaining broad economic policy continuity.

The first round featured among the highest rates of voter turnout in recent history, with participation of 19.3m of the country's 36m registered voters. Mr Duque obtained 7.6m votes (39.1% of the total), while Mr Petro received 4.9m votes, a 25.1% share. As expected, Sergio Fajardo, of the centre-left Coalición Colombia, came third; however, his final vote tally was higher than anticipated, at 4.6m (a 23.7% share), surprisingly close to Mr Petro's. This has increased the value of Mr Fajardo's support in the run-off.

Germán Vargas Lleras, of the Mejor Vargas Lleras coalition, obtained 1.4m votes (7.3%), and Humberto de la Calle, of the centre-left Partido Liberal (PL), obtained 400,000 (2.1%). The fourth- and fifth-placed candidates' smaller shares of the vote will make their political role in the run-off less important than Mr Fajardo's, although both could still play a significant role in the second round.

Duque to attract the political class

Ideological similarities should facilitate an alliance between Mr Duque and Mr Vargas Lleras, in spite of some earlier personal friction between members of the two campaigns, most prominently between Mr Vargas Lleras and the former president, Álvaro Uribe (2002‑10), the leader of the CD. In the coming days Mr Duque is also likely to receive the endorsement of other parties that backed Mr Vargas Lleras, including the right-wing Cambio Radical (CR, Mr Vargas Lleras's party) and the Partido Conservador (PC).

Backing from the voter base of other right-leaning parties would not only help Mr Duque's second-round campaign, it would also produce benefits for a potential administration led by Mr Duque. Given the strong presence of these parties in Congress (the CD holds 19 out of 108 seats in the Senate—the upper house—, the CR has 16 and the PC holds 15), Mr Duque would, assuming that he wins, seek to strike deals with other political forces in order to build a governing coalition that will aid policymaking.

The losing contenders are yet to announce who will they back in the run-off, except for Mr de la Calle, who has stated that his supporters are free to decide how to allocate their second-round votes. It is possible that a vast majority of his support base will refrain from participating or cast blank votes (the latter accounted for 2% of the total in the first round).

Fajardistas and Bogotá will be key for both Duque and Petro

The support of the fajardistas (Mr Fajardo's supporters) will have a significant impact on the June 17th vote, but it is not obvious which candidate will garner the most support from this group. Mr Duque's conciliatory tone and a more centrist message, which were clear during his victory speech on May 27th, could leave him best placed to pick up support from Mr Fajardo's base. But other voters will be wary about supporting Mr Duque, given that he is perceived to represent the political establishment—substantial public disillusionment with traditional politics was evident during the campaign period ahead of the first round. Although Mr Duque's relative youth (he is 41) and somewhat progressive ideas in areas such as the environment and entrepreneurship could help to counter this perception, the fact that he is running for Mr Uribe's party will be a significant barrier for Mr Duque among some voters. Attracting fajardistas from Bogotá will be particularly challenging, as the capital city has proven itself a stronghold for voters willing to back non-traditional candidates like Mr Petro, a former mayor of Bogotá. In the first round, 1.2m Bogotá voters backed Mr Fajardo; Messrs Petro and Duque respectively received 1.1m and 980,000 votes from voters in the capital.

Suggesting that Mr Duque will not have an easy time attracting fajardistas, the centre-left Partido Verde (PV), a member of Mr Fajardo's electoral coalition that boasts a very strong electoral base in Bogotá, has already declared that it will not endorse the CD candidate—although this does not automatically mean that it will support Mr Petro. Instead, PV voters may well refrain from voting or cast blank protest votes. Meanwhile, it is likely that the left-wing Polo Democrático Alternativo (Polo), another member of Mr Fajardo's Coalición Colombia, will formalise its support for Mr Petro. That said, Polo appears to have tacitly supported Mr Petro even before the first round, and thus may not provide a many additional votes for Mr Petro in the run-off.

Tension and risks ahead

Notwithstanding attempts to capture centrist voters, a second-round race featuring candidates from the right and left of the political spectrum suggests that the campaign will be polarising, and could become hostile. Mr Petro's left-wing views and volatile tone, which he will need to soften in order to capture centrist voters, will continue to create unease—as did his earlier claims that electoral fraud could take place in the first round.

For Mr Duque, the question of Mr Uribe's influence in his administration could be problematic. Mr Duque is considered to be Mr Uribe's protégé. The former president is a polarising figure who is popular with many voters but unpopular with many others. Mr Duque's negative views of the peace deal with FARC rebels secured by the current president, Juan Manuel Santos, will also be put to the test. Although the peace process will feature more heavily in the run-up to the second round, the electorate's main concerns can be found elsewhere, covering areas including corruption, unemployment, and crime and security.

Policy continuity and improved prospects under a Duque presidency

We continue to forecast that Mr Duque will emerge as the victor of the mid-June run-off. Upon taking office for a four-year term in August, he is expected to maintain broad economic policy continuity, characterised by further fiscal reform and business incentives, which are expected to benefit Colombia's macroeconomic environment. On the political front, Mr Duque is likely to face more daunting challenges owing to political polarisation and fragmentation in Congress. His plans to introduce some modifications to the peace deal with the FARC may find legal obstacles, while his intention to undertake judicial reform and tackle corruption will meet political resistance. However, despite his short experience in office, Mr Duque has thus far shown an ability to be a good mediator and consensus-builder, and we thus expect him to conduct an effective administration through political dialogue.